diff options
Diffstat (limited to 'lib/crypto/poly1305-donna32.c')
| -rw-r--r-- | lib/crypto/poly1305-donna32.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/lib/crypto/poly1305-donna32.c b/lib/crypto/poly1305-donna32.c new file mode 100644 index 000000000000..3cc77d94390b --- /dev/null +++ b/lib/crypto/poly1305-donna32.c @@ -0,0 +1,204 @@ +// SPDX-License-Identifier: GPL-2.0 OR MIT +/* + * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. + * + * This is based in part on Andrew Moon's poly1305-donna, which is in the + * public domain. + */ + +#include <linux/kernel.h> +#include <asm/unaligned.h> +#include <crypto/internal/poly1305.h> + +void poly1305_core_setkey(struct poly1305_core_key *key, const u8 raw_key[16]) +{ + /* r &= 0xffffffc0ffffffc0ffffffc0fffffff */ + key->key.r[0] = (get_unaligned_le32(&raw_key[0])) & 0x3ffffff; + key->key.r[1] = (get_unaligned_le32(&raw_key[3]) >> 2) & 0x3ffff03; + key->key.r[2] = (get_unaligned_le32(&raw_key[6]) >> 4) & 0x3ffc0ff; + key->key.r[3] = (get_unaligned_le32(&raw_key[9]) >> 6) & 0x3f03fff; + key->key.r[4] = (get_unaligned_le32(&raw_key[12]) >> 8) & 0x00fffff; + + /* s = 5*r */ + key->precomputed_s.r[0] = key->key.r[1] * 5; + key->precomputed_s.r[1] = key->key.r[2] * 5; + key->precomputed_s.r[2] = key->key.r[3] * 5; + key->precomputed_s.r[3] = key->key.r[4] * 5; +} +EXPORT_SYMBOL(poly1305_core_setkey); + +void poly1305_core_blocks(struct poly1305_state *state, + const struct poly1305_core_key *key, const void *src, + unsigned int nblocks, u32 hibit) +{ + const u8 *input = src; + u32 r0, r1, r2, r3, r4; + u32 s1, s2, s3, s4; + u32 h0, h1, h2, h3, h4; + u64 d0, d1, d2, d3, d4; + u32 c; + + if (!nblocks) + return; + + hibit <<= 24; + + r0 = key->key.r[0]; + r1 = key->key.r[1]; + r2 = key->key.r[2]; + r3 = key->key.r[3]; + r4 = key->key.r[4]; + + s1 = key->precomputed_s.r[0]; + s2 = key->precomputed_s.r[1]; + s3 = key->precomputed_s.r[2]; + s4 = key->precomputed_s.r[3]; + + h0 = state->h[0]; + h1 = state->h[1]; + h2 = state->h[2]; + h3 = state->h[3]; + h4 = state->h[4]; + + do { + /* h += m[i] */ + h0 += (get_unaligned_le32(&input[0])) & 0x3ffffff; + h1 += (get_unaligned_le32(&input[3]) >> 2) & 0x3ffffff; + h2 += (get_unaligned_le32(&input[6]) >> 4) & 0x3ffffff; + h3 += (get_unaligned_le32(&input[9]) >> 6) & 0x3ffffff; + h4 += (get_unaligned_le32(&input[12]) >> 8) | hibit; + + /* h *= r */ + d0 = ((u64)h0 * r0) + ((u64)h1 * s4) + + ((u64)h2 * s3) + ((u64)h3 * s2) + + ((u64)h4 * s1); + d1 = ((u64)h0 * r1) + ((u64)h1 * r0) + + ((u64)h2 * s4) + ((u64)h3 * s3) + + ((u64)h4 * s2); + d2 = ((u64)h0 * r2) + ((u64)h1 * r1) + + ((u64)h2 * r0) + ((u64)h3 * s4) + + ((u64)h4 * s3); + d3 = ((u64)h0 * r3) + ((u64)h1 * r2) + + ((u64)h2 * r1) + ((u64)h3 * r0) + + ((u64)h4 * s4); + d4 = ((u64)h0 * r4) + ((u64)h1 * r3) + + ((u64)h2 * r2) + ((u64)h3 * r1) + + ((u64)h4 * r0); + + /* (partial) h %= p */ + c = (u32)(d0 >> 26); + h0 = (u32)d0 & 0x3ffffff; + d1 += c; + c = (u32)(d1 >> 26); + h1 = (u32)d1 & 0x3ffffff; + d2 += c; + c = (u32)(d2 >> 26); + h2 = (u32)d2 & 0x3ffffff; + d3 += c; + c = (u32)(d3 >> 26); + h3 = (u32)d3 & 0x3ffffff; + d4 += c; + c = (u32)(d4 >> 26); + h4 = (u32)d4 & 0x3ffffff; + h0 += c * 5; + c = (h0 >> 26); + h0 = h0 & 0x3ffffff; + h1 += c; + + input += POLY1305_BLOCK_SIZE; + } while (--nblocks); + + state->h[0] = h0; + state->h[1] = h1; + state->h[2] = h2; + state->h[3] = h3; + state->h[4] = h4; +} +EXPORT_SYMBOL(poly1305_core_blocks); + +void poly1305_core_emit(const struct poly1305_state *state, const u32 nonce[4], + void *dst) +{ + u8 *mac = dst; + u32 h0, h1, h2, h3, h4, c; + u32 g0, g1, g2, g3, g4; + u64 f; + u32 mask; + + /* fully carry h */ + h0 = state->h[0]; + h1 = state->h[1]; + h2 = state->h[2]; + h3 = state->h[3]; + h4 = state->h[4]; + + c = h1 >> 26; + h1 = h1 & 0x3ffffff; + h2 += c; + c = h2 >> 26; + h2 = h2 & 0x3ffffff; + h3 += c; + c = h3 >> 26; + h3 = h3 & 0x3ffffff; + h4 += c; + c = h4 >> 26; + h4 = h4 & 0x3ffffff; + h0 += c * 5; + c = h0 >> 26; + h0 = h0 & 0x3ffffff; + h1 += c; + + /* compute h + -p */ + g0 = h0 + 5; + c = g0 >> 26; + g0 &= 0x3ffffff; + g1 = h1 + c; + c = g1 >> 26; + g1 &= 0x3ffffff; + g2 = h2 + c; + c = g2 >> 26; + g2 &= 0x3ffffff; + g3 = h3 + c; + c = g3 >> 26; + g3 &= 0x3ffffff; + g4 = h4 + c - (1UL << 26); + + /* select h if h < p, or h + -p if h >= p */ + mask = (g4 >> ((sizeof(u32) * 8) - 1)) - 1; + g0 &= mask; + g1 &= mask; + g2 &= mask; + g3 &= mask; + g4 &= mask; + mask = ~mask; + + h0 = (h0 & mask) | g0; + h1 = (h1 & mask) | g1; + h2 = (h2 & mask) | g2; + h3 = (h3 & mask) | g3; + h4 = (h4 & mask) | g4; + + /* h = h % (2^128) */ + h0 = ((h0) | (h1 << 26)) & 0xffffffff; + h1 = ((h1 >> 6) | (h2 << 20)) & 0xffffffff; + h2 = ((h2 >> 12) | (h3 << 14)) & 0xffffffff; + h3 = ((h3 >> 18) | (h4 << 8)) & 0xffffffff; + + if (likely(nonce)) { + /* mac = (h + nonce) % (2^128) */ + f = (u64)h0 + nonce[0]; + h0 = (u32)f; + f = (u64)h1 + nonce[1] + (f >> 32); + h1 = (u32)f; + f = (u64)h2 + nonce[2] + (f >> 32); + h2 = (u32)f; + f = (u64)h3 + nonce[3] + (f >> 32); + h3 = (u32)f; + } + + put_unaligned_le32(h0, &mac[0]); + put_unaligned_le32(h1, &mac[4]); + put_unaligned_le32(h2, &mac[8]); + put_unaligned_le32(h3, &mac[12]); +} +EXPORT_SYMBOL(poly1305_core_emit); |